Internal j-shaped valve for flexible bags



May 30, 1967 G. M. PRAM. 3,322,327

INTERNAL J-SHAPED VALVE FOR FLEXIBLE BAGS Filed June 2, 1966 m @MWUnited States Patent Gli 3,322,327 INTERNAL J-SHAPED VALVE FOR FLEXIBLEBAGS George M. Prall, Barrington, lill., assignor to National Distillersand Chemical Corporation, New York, N.Y., a corporation of VirginiaFiled June 2, 1966, Ser. No. 554,709 3 Claims. (Cl. 229-625) Thisinvention relates to a novel patch valve for plastic bags, and morespecifically relates to the use of a novel internal I-shaped insert fordefining an internal valve for a plastic bag which provides improvedvalve integrity.

The use of valve openings in plastic bags is well known to the art,where such valves can accommodate a filling spout insert into a closedbag. An internal patch having a free internal open end is commonlyplaced over the interior of a slotted opening in the wall of the bag toprevent the escape of the bag contents after it is filled, hereinafterreferred to as sifting of the bag contents.

In accordance with the present invention, the internal patch is formedof a light gauge plastic film which is heat sealed over the interiorsurface of the slot in the bag wall. The patch has a J-shaped fold withboth the short and long leg of the J-shaped body having their common endsealed in front of the slot, with the body of each leg extending beyondthe rear of the slot, thereby to provide improved valve integrity.

When using the novel J -shaped valve in the above noted manner, thevalve offers two free edges internally of the bag to prevent sifting ofthe bag contents from the valve after filling. The interior-most portionof the l-shaped iiap acts in a manner similar to any type of internalpatch and will crumple as the contents of the bag move toward the valveopening when the bag is removed from the lling spout and placed in somedifferent position. This crumpling action on the main body or long legof the J- shaped valve prevents most of the bag contents from siftingfrom the valve.

In accordance with the invention, however, the smaller J-portion of theflap defines a second edge just inside the bag opening and will furtherprevent the sifting of residual material left in the valve area by thewithdrawal of the loading spout, as well as to preventing sifting ofmaterial entering the valve area before it has been fully sealed by themajor portion of the inner flap.

Accordingly, a primary object of this invention is to provide a novelinternal valve for plastic bags which has improved valve action.

Yet another object of this invention is to provide the effect of twoserially connected valve fiaps adjacent the valve slot of a plastic bagwhereby the last valve controls any sifting through the first and majorvalve portion.

These and other objects of this invention will become apparent from thefollowing description when taken in connection with the drawings, inwhich:

FIGURE l is an exploded perspective view showing a bag body and theJ-shaped internal flap which is to be connected thereto.

FIGURE 2 illustrates the l-shaped internal valve of FIGURE l when sealedinto the open end of the bag and across the slotted opening in the bag.

FIGURE 3 is a front view of the bag of FIGURE 2 after the upper edge hasbeen sealed to close the bag and complete the valve connection.

FIGURE 4 is a cross-sectional view of FIGURE 3 taken across the line4--4 in FIGURE 3.

FIGURE 5 is a cross-sectional View of FIGURE 3 taken across the line 5-5in FIGURE 3.

Referring fiirst to FIGURE 1, there is illustrated therein a typical bagof any suitable plastic material which has 3,322,327 Patented May 30,1967 ice yfront and rear panels 11 and 12 joined in FIGURE l by the sidegussets 13 and 14. It will become apparent that the present invention isapplicable to any type of bag and that the gusseted bag of FIGURE 1 isused for illustrative purposes only.

The bottom of bag 10 then has a heat seal 15 extending thereacross toseal panels 11 and 12 at their bottom. The upper portion of panel 11then has a slot 16 extending therethrough which will provide access fora filling spout to the interior of the bag when the bag is closed. Aninternal patch valve 17 of a thin exible thermoplastic material is thenplaced across the interior of slot 16 to prevent sifting of the contentsof the bag 10 after the bag is filled through slot 16.

In accordance with the invention, the internal valve 17 has a J-shape,as illustrated in FIGURE 1, which has a relatively long body portion 13and an inwardly turned relatively short body portion 19. The patch 17 isthen applied to the open bag, as shown in FIGURE 2, wherein the bottomregion of the J-shape is sealed in front of slot 16 as along a heat seal2l), while the lower side of l-shaped valve insert 17 is sealed along aportion thereof by the heat seal 21. The relatively long fiap portion 18extends beyond the left-hand end of seal 21 and appreciably beyond theslot 16, while the relatively short section 19 of patch valve 17 extendsjust beyond slot 16.

After the l-shaped insert 17 is sealed to the bag, as shown in FIGURE 2,the upper end of the bag is closed by a heat seal 22, shown in FIGURE 3,which extends completely along the upper e-nd of the bag and extendsfrom the front panel 11 to the rear Apanel 12 of the bag. -Note that thepatch valve sections 18 and 19 will be included in this seal Where theyare interposed between panels 11 and 12.

The section 18 of the insert 17 will now operate in the manner of astandard internal flap in a valve bag whereby, as may be best understoodfrom FIGURES 4 and 5, a filling spout can be inserted into the bagthrough slot 16 a-nd along the channel 23 (FIGURE 4) defined betweenpanel 11 and the opposing surface section 13 of the valve. `Once thespout has filled the bag and is removed from channel 23, the ap 18 cancrumple against the inner surface of panel 18 to prevent sifting of thebag contents out through slot 16.

In accordance with the invention, the use of the I- shaped flap providesa second valving ap comprised of section 19 which extends just beyondthe slot 16, as shown in FIGURE 4, to serve as a second-ary valve toprevent the sifting of material from the bag which may have been trappedin channel 23 or otherwise enters channel 23. Therefore, the novel I-shaped valve provides an improved valve action to substantiallyeliminate all sifting of the bag contents.

Although this invention has been described with respect to its preferredembodiments, it should be understood that many variations andmodifications will now be obvious to those skilled in the art, and it ispreferred, therefore, that the scope of the invention be limited not bythe specific disclosure herein, but only by the appended claims.

The embodiments of the invention in which an exlusive privilege orproperty is claimed are defined as follows:

1. A valve for a iiexible plastic bag; said plastic bag having a frontpanel having an interior surface; said front panel havin-g a slottherein; said valve comprising a relatively long fiexible plastic sheetand a relatively short flexible plastic sheet; first, second and thirdheat seals connecting said relatively short and relatively long plasticsheets to said interior surface of said front panel and across saidvalve; said first heat seal extending parallel to said slot andlaterally displaced therefrom and extending through said fro-nt paneland one end region of each of said relatively short and relatively longsheets; said second and third heat seals extending perpendicular to saidslot and passing across regions adjacent the ends of said slot; saidsecond and third heat seals extending through said front panel andthrough opposite side edges of each of said relatively long andrelatively short sheets; said relatively shor-t sheets interposedbetween said interior surface of said front panel and a portion of saidrelatively long sheet; said relatively short sheet having a free edgeextending beyond said slot; said relatively long sheet having a freeedge extending beyond said free edge of said relatively short sheet.

2. The valve as set forth in claim 1 wherein said relatively long sheetand relatively short sheet are comprised of an integral sheet of plasticmaterial bent in the form of a I.

3. The valve as set forth in claim 1 wherein said slot extends in thedirection of the length of said exible plastic bag land adjacent oneside edge thereof; said second heat seal extending along the full topedge of said bag and sealing closed the top of said bag.

References Cited UNITED STATES PATENTS 3,180,558 4/1965 Quaadgrass etal. 229-625 3,197,119 7/1965 Hartig et al. 22962.5 3,268,152 8/1966SWa-rtZ 229-62.5 FOREIGN PATENTS 954,273 4/ 1964 Great Britain.

JOSEPH R. LECLAIR, Primary Examiner. D. M. BOCKENE-K, AssistantExaminer.

1. A VALVE FOR A FLEXIBLE PLASTIC BAG; SAID PLASTIC BAG HAVING A FRONTPANEL HAVING AN INTERIOR SURFACE; SAID FRONT PANEL HAVING A SLOTTHEREIN; SAID VALVE COMPRISING A RELATIVELY LONG FLEXIBLE PLASTIC SHEETAND A RELATIVELY SHORT FLEXIBLE PLASTIC SHEET; FIRST, SECOND AND THIRDHEAT SEALS CONNECTING SAID RELATIVELY SHORT AND RELATIVELY LONG PLASTICSHEETS TO SAID INTERIOR SURFACE OF SAID FRONT PANEL AND ACROSS SAIDVALVE; SAID FIRST HEAT SEAL EXTENDING PARALLEL TO SAID SLOT ANDLATERALLY DISPLACED THEREFROM AND EXTENDING THROUGH SAID FRONT PANEL ANDONE END REGION OF EACH OF SAID RELATIVELY SHORT AND RELATIVELY LONGSHEETS; SAID SECOND AND THIRD HEAT SEALS EXTENDING PERPENDICULAR TO SAIDSLOT AND PASSING ACROSS REGIONS ADJACENT THE ENDS OF SAID SLOT; SAIDSECOND AND THIRD HEAT SEALS EXTENDING THROUGH SAID FRONT PANEL ANDTHROUGH OPPOSITE SIDE EDGES OF EACH OF SAID RELATIVELY LONG ANDRELATIVELY SHORT SHEETS; SAID RELATIVELY SHORT SHEETS INTERPOSED BETWEENSAID INTERIOR SURFACE OF SAID FRONT PANEL AND A PORTION OF SAIDRELATIVELY LONG SHEET; SAID RELATIVELY SHORT SHEET HAVING A FREE EDGEEXTENDING BEYOUND SAID SLOT; SAID RELATIVELY LONG SHEET HAVING A FREEEDGE EXTENDING BEYOND SAID FREE EDGE OF SAID RELATIVELY SHORT SHEET.